The present applicant has previously patented several ground anchors of the general class described; viz., U.S. Pat. Nos. 3,076,532; 3,197,928; 3,328,928 and 3,636,670. Each has progressively improved upon the design of its predecessors as experience has taught the need for further refinements economy of production, ability to withstand rough usage, etc.
It is well known that volleyball, when skillfully played, is the most rugged of all net games, and the net and supports or posts are subjected to considerable punishment. Unless adequate ground anchors are provided, the supports fail and the ground anchors must be reset or replaced, unless, of course, permanent anchors are used, which is not compatible with portability, as where the volleyball set -- comprising net, posts and ground anchors -- is used at home, playgrounds, picnic areas and the like. It is vital that a simple, sturdy and low-cost anchor be provided and among the characteristics such an anchor must possess are ease of installation, strength, durability and yieldability. Ease of installation is achieved by providing a helical ground-penetrating part that may be screwed into the ground, using the aboveground part as a crank or handle. This is known from applicant's prior patents and others. Strength and durability are obtained by making the anchor of rod-like steel having the desired degree of flexibility. Yieldability of the above-ground part, so that the anchor can yield to forces applied by the players to the net and hence to the posts, is achieved by proper design of the above-ground part, whereby this part can flex in bending and in torque and be able to recover its original shape or posture when the forces disappear.
According to the present invention, the ground anchor has improved strength and flexibility by a special design of the above-ground part, here of hairpin form having a pair of legs fixed to and extending away from the top of the helix to a bight which in turn rigidly carries a receiver means for supporting a post. Preferably, one of the legs is an integral extension of the top turn of the helix and the other leg is welded to the top of the helix to afford an integrated structure. Further, the post-supporting member is secured to the bight of the hairpin by a double-plate construction including one plate above and a second plate below the bight, and the plates, post-supporting member and bight are all rigidly secured together. Additionally, the bottom plate is of ramp- or skid-like form so that the anchor may be readily screwed into the ground without causing the bight to dig into the turf or sod.
Still further, the formation of the anchor is such that when initially screwed into the ground until the bight ramp contacts the ground, the top portion of the helix is still somewhat above the ground and the post-supporting member is upright, and, when further turns are applied to the anchor by means of the post-supporting member and hairpin portion as a crank or handle, the helix goes further into the ground, the junction of the hairpin and helix flexes and the post-supporting member is caused to tilt toward the helix angle extended. Thus, when both anchors are installed and the net posts are in place, the posts diverge upwardly, and the net may be properly tensioned by drawing the posts into vertical parallelism, the hairpin flexing to enable this result. The double or hairpin leg increases the strength of the anchor and thus adds to the ability of the anchor to resist destruction. Other features and advantages will become apparent as a preferred embodiment is disclosed hereinafter.